1. Field of the Invention
The present invention relates to a rear suspension for a four-wheel steering system, and in particular to a rear suspension which can control the position of the rear wheels in accordance with a vehicle's steering direction and speed.
2. Description of Related Art
In general, the steering system is a means by which the driver of a vehicle is able to control the position of the front wheels. The system must provide ease of handling, good directional control, and stability. This is achieved by the steering system in conjunction with the suspension system.
However, the front wheel steering system has problems that when the vehicle is driven at high speed, the rear wheels tend to follow the vehicle body during a turn such that a center of the vehicle is abruptly declined to deteriorate the stability and unequal tire wear occurs.
Further, when the vehicle is driven at low speed, the front wheel steering system cannot sufficiently reduce a turning radius.
To solve the above described problems of the front wheel steering system, many types of four-wheel steering systems have been proposed. The four-wheel steering system controls the steering angle of the rear wheels as well as the front wheels. Advantages of the four-wheel steering system includes a reduced turning radius, better vehicle control during lane changes, and easier parallel parking. There are two general types of the four-steering systems: mechanically controlled and electronically controlled systems.
However, all of the conventional four-wheel steering systems are designed such that when the steering wheel is turned, the front and rear wheels are turned simultaneously. Accordingly, a complicated connecting structure is required between the front and rear wheels.